It is recognized that nuclear heat could be converted into electricity using a high temperature gas reactor (HTGR) -- magnetohydrodynamic generator (MHD) -- steam cycle with an overall efficiency higher than 50%, provided the gas temperature from the reactor reaches about 1600.degree.C. The outlet gas temperature from presently available HTGRs is not sufficiently high to reach this efficiency, and is not likely to reach this temperature for the next several years. There remains, therefore, a qualitative gap between the maximum outlet temperature of existing and expected HTGRs and the minimum temperature necessary for efficient operation of the HTGR-MHD-steam cycle.
The process and apparatus of this invention makes possible the efficient utilization HTGR for the production of energy in a closed cycle utilizing MHD. The invention, however, is not limited to HTGR as the primary heat source.